I'm going to risk asking something that is really better placed in the broadband sections, but nevermind your WiFi... is your broadband working? (WiFi is just the connection between your devices and the router - it's the onward broadband from the router to the internet that's more important).
Having said that... if you potentially have broadband issues and your TV is breaking up, you may well have a network fault on your hands.
As newapollo mentions, 0800 5610061 often lists localised faults, otherwise report your fault (or you'll just be waiting for others to do so instead) - 150 from a VM landline or 0345 4541111 from any other phone.
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